You’ve called Republican presidential hopeful Newt Gingrich a very good moral psychologist. What do you mean?
Gingrich is very skilled at manipulating moral sentiments. He understands visceral morality. In the 1990s, he came up with a list of words Republicans should use when talking about Democrats, including “dirty,” “sleazy,” “cheating.” If you talk about “a dirty idea that will bring us down into the gutter,” the words are very powerful. Ronald Reagan was a skilled moral psychologist, too. In fact, for the past 30 or 40 years Republicans have known how to talk in ways that push buttons.

Are Democrats less skilled at pushing buttons?
Democrats talk about programs like social security or Medicare but it’s not clear to most voters what Democrats’ core moral values are.

What should they do differently?
To get folks to vote for you—and go on voting for you—you need to tap into several of their moral foundations. When Barack Obama and the Democrats were changing the health care system, couldn’t they at least have put on a show of worrying about cheaters—a concern that is stronger on the right than on the left? Couldn’t they have pretended to care about catching all the doctors and lawyers who are in cahoots with patients to rip off the system?

Politics doesn’t sound like the typical terrain for a psychologist. How did you become involved?
I began as a cultural psychologist in the early 1990s, looking at how morality varies across nations such as Brazil, India, and the U.S. It was only in 2004 that I got interested in political ideologies and cultures, and in looking at liberals and conservatives as though they were different nations.

You argue that the key to the partisan nature of U.S. politics today is to understand the concept of “righteousness.” Why is that?
In its original meaning, righteous means just, upright and virtuous. I’m using the word in a colloquial sense: self-righteous, judgmental, moralistic. I believe our minds evolved to be moralistic. This may sound lamentable, especially to those of us who think we should be less judgmental. But the evolutionary story I tell in my book is one where judgmentalism—the ability to create moral matrices and punish, shame and ostracize those who don’t behave rightly—was in fact the great breakthrough. We wouldn’t be talking on the phone now if we didn’t have righteous minds. We’d be like chimps, brilliant individuals who are poor at cooperating and collaborating.

So cooperation, fuelled by righteousness, makes us civilized?
People have long been looking for what distinguishes us from chimps. Is it our thumbs, upright posture, language? I was very influenced by the psychologist Michael Tomasello, whose work shows that chimps are as smart as 3-year-old kids at most physical tasks. But expect them to liaise with another individual, sharing a representation of what they are doing, and chimps do poorly, while 3-year-olds are geniuses. This was the birth of what he calls “shared intentionality,” which includes shared ideas about what we’re trying to do, and how we should do it. This ability allows us all to judge and collectively condemn those who can’t or won’t play along.

Only once we could share mental representations could we do things such as divide labor so some hunt and some stay home and tend the fire, while we all share the spoils. Tomasello’s experiments show that if kids pull on a string together and it gives them unequal rewards, the kids will spontaneously equalize the rewards. They have the sense that we did this together therefore we must split the spoils. Chimps don’t seem to do this.

But with all this cooperation in the air, how come things go so wrong?
Morality is a basic aspect of human nature just like, say, musicality or language. Morality binds people into groups. It gives us tribalism, it gives us genocide, war, and politics. But it also gives us heroism, altruism, and sainthood. This is all part of our “groupish” nature.

Given this groupish nature and strong belief systems, will we demonize non-believers?
Dividing into teams doesn’t necessarily mean denigrating others. Studies of groupishness have generally found that groups increase in-group love far more than they increase out-group hostility. Dividing into groups increases social capital and trust, it’s generally a good thing. But when it crosses the line from “we disagree with you” to “you are evil,” then people begin to believe the ends justify the means and all hell breaks loose. That’s where we are now in the U.S. where politicians and their consultants will do all kinds of devious, underhand, sometimes illegal things to help their party win and to damage the other party. They think that if you’re fighting Satan, it’s OK to break the rules.

Where can we see this demonization in action?
In the U.S., something called Oppo Research, or “opposition research,” is a huge business, and some of it is illegal. You go through dumpsters, tap phones—try to get anything that will destroy careers. This is terrible stuff. Who would want to go into public service now? There are lots of highly paid people trying to destroy you, and if they have to lie or make up stuff to do it, they will. But these people think they’re ultimately doing good.

What’s the solution? Understand the moral motivations of the other side?
Yes. In my moral psychology class where I work with students for 14 weeks, I always find that the students don’t change their politics—they don’t become more centrist—but they stop demonizing others and actually become interested in listening to the other side.

What about extreme groups like the Tea Party?
Liberals have difficulty understanding the Tea Party because they think it is a bunch of selfish racists. But I think the Tea Party is driven in large part by concerns about fairness. It’s not fairness as equality of outcomes, it’s fairness as karma—the idea that good deeds will lead to good outcomes and bad deeds will lead to suffering. Many conservatives believe the Democratic party has been the anti-karma party since the ’60s. It’s the party that says, you got pregnant? Don’t worry, have an abortion. You got addicted to drugs? Don’t worry, we’ll give you methadone. It’s the party that absolves you from moral irresponsibility.

The Tea Partiers don’t hate all government: just government they see as subverting karma, subverting moral responsibility. This hatred is, I think, a derivative of their love of proportionality. They’re perfectly happy with social security, a retirement scheme which Franklin D. Roosevelt deliberately portrayed as a form of fairness, you pay in and you get out.

Has your research changed what you think about politics?
I got into this as a partisan liberal, who was trying to help Democrats overcome decades of cluelessness on moral psychology. While trying to understand conservatives and libertarians, I’ve realized they are right about a number of things. So if you just let one team—liberals, conservatives or libertarians—run everything, they’re going to screw up because they don’t have a full tool kit. My highest hope for my book is that it will help people get some perspective on moral disagreements. We’re all morally motivated (apart from 1 percent who are psychopaths). Each side sees truths about how to run a good society which the other side can’t see, so we need everyone’s insights.